The first and most important step in processing data in transversely isotropic (TI) media for which velocities vary with depth is parameter estimation. The multilayer normal-moveout (NMO) equation for a dipping reflector provides the basis for extending the TI velocity analysis of Alkhalifah and Tsvankin to vertically inhomogeneous media. This NMO equation is based on a root-mean-square (rms) a...

Seismic methods play an important role in the development of tight fractured reservoirs with substantial spatial variability of fracture density. Here, we apply a comprehensive processing sequence designed for layered azimuthally anisotropic media to wide-azimuth P-wave data acquired over a fractured gas sand formation in the Rulison field, Colorado. The main processing steps include nonhyperbo...

I show that, by estimating local event slopes in prestack seismic reflection data, it is possible to accomplish all common time-domain imaging tasks, from normal moveout to prestack time migration, without the need to estimate seismic velocities or any other attributes. Local slopes contain complete information about the reflection geometry. Once they are estimated, seismic velocities and all o...

Azimuthal anisotropy or lateral velocity variations cause azimuthal variations in moveout velocity which can lead to seismic image degradation if not properly handled. In cases where apparent azimuthally anisotropic moveout is present, a single picked velocity is inadequate to flatten an event on a 3D CMP gather. Conventional velocity analysis techniques require a significant amount of time and...

Near-surface velocity gradients can be large enough to inhibit normal moveout corrections on a single pass of a complete shallow velocity function during routine shallow seismic reflection processing flows. Stretch artifacts that are the result of inversion and compression within the highest rate of velocity change portion of the shot gather can stack coherently on CMP sections. The constant ve...